PEEFACE 



The present volume is an instalment of that part of the 

 treatise dealing with the great phylum Appendiculata — a 

 phylum which includes the Arthropoda, Chsetopoda, and 

 Eotifera. Dr. Caiman having finished the present description 

 of the Crustacea, it has been considered advisable to publish 

 it at once, without waiting either for the general intro- 

 duction on the classification and characters of the phylum 

 Appendiculata or for the completion of the fascicles devoted to 

 the Peripatoids, Chilopods, Arachnids, Chilognaths, Hexapod 

 Insects, Chsetopods, and Rotifers. 



E. RAY LANKESTER. 



January 1909. 



